[Java][Servlet] メール送信機能（複数メール・単一接続）＆受信テスト

context.xml

<Context>
  <Resource name="mail/Session" auth="Container"
            type="javax.mail.Session"
            mail.smtp.host="localhost"
            mail.from="[email protected]"
            mail.debug="false"
            />
<!--
  <Resource name="mail/Session" auth="Container"
            type="javax.mail.Session"
            mail.smtp.host="smtp.gmail.com"
            mail.smtp.port="587"
            mail.smtp.auth="true"
            mail.smtp.starttls.enable="true"
            mail.from="[email protected]"
            mail.debug="true"
            />
-->
</Context>

MailPop3.properties

mail.pop3.host=localhost
mail.debug=false

MailSender.java

public interface MailSender extends Closeable {
  void connect() throws IOException;
  void send(String address, String subject, String body);
}

MailSenderImpl.java

import javax.mail.*;

public class MailSenderImpl implements MailSender {
  private final Session session;
  private final Transport transport;

  public MailSenderImpl(Session session) {
    this.session = session;
    try {
      this.transport = session.getTransport("smtp");
    } catch (NoSuchProviderException e) {
      throw new RuntimeException(e);
    }
  }

  @Override
  public void connect() throws IOException {
    try {
      transport.connect();
    } catch (MessagingException e) {
      throw new IOException(e);
    }
  }

  @Override
  public void send(String address, String subject, String body) {
    try {
      MimeMessage message = createMessage(address, subject, body);
      transport.sendMessage(message, message.getAllRecipients());
    } catch (MessagingException e) {
      throw new RuntimeException(e);
    }
  }

  private MimeMessage createMessage(String address, String subject, String body)
      throws MessagingException {
    final String charset = "ISO-2022-JP";
    MimeMessage message = new MimeMessage(session);
    message.setRecipients(Message.RecipientType.TO,
        new InternetAddress[] {new InternetAddress(address)});
    message.setSubject(subject, charset);
    message.setText(body, charset);
    return message;
  }

  @Override
  public void close() throws IOException {
    try {
      transport.close();
    } catch (MessagingException e) {
      throw new IOException(e);
    }
  }
}

MailSenderTest.java

public class MailSenderTest {
  private MailTestHelper mail1;
  private MailTestHelper mail2;
  private MailTestHelper mail3;

  @Before
  public void setUp() throws Exception {
    Session pop3 = createMailSession("/mail/MailPop3.properties", "user1", "user1");
    mail1 = new MailTestHelper(pop3, "[email protected]", "件名test1");
    mail2 = new MailTestHelper(pop3, "[email protected]", "件名test2");
    mail3 = new MailTestHelper(pop3, "[email protected]", "件名test1");
    deleteMail();
  }

  @After
  public void tearDown() throws Exception {
    deleteMail();
  }

  private void deleteMail() {
    mail1.delete();
    mail2.delete();
    mail3.delete();
  }

  @Test
  public void testMailSender() throws IOException {
    MailSender sender = new MailSenderImpl(
        createMailSession("/mail/MailSmtp.properties", null, null));

    sender.connect();
    try {
      sender.send(mail1.getAddress(), mail1.getSubject(), "本文test1\n2行目");
      sender.send(mail2.getAddress(), mail2.getSubject(), "本文test2");
      sender.send(mail3.getAddress(), mail3.getSubject(), "本文test3");
    } finally {
      sender.close();
    }

    assertEquals("本文test1\r\n2行目", mail1.getContent());
    assertEquals("本文test2", mail2.getContent());
    assertEquals("本文test3", mail3.getContent());
  }

  private Session createMailSession(String path, final String user,
      final String password) {
    Properties props = loadProperties(path);
    if (StringUtils.isEmpty(user)) {
      return Session.getDefaultInstance(props);
    } else {
      Authenticator auth = new Authenticator() {
        protected PasswordAuthentication getPasswordAuthentication() {
          return new PasswordAuthentication(user, password);
        }
      };
      return Session.getInstance(props, auth);
    }
  }

  private Properties loadProperties(String propPath) {
    try {
      Properties res = new Properties();
      res.load(getClass().getResourceAsStream(propPath));
      return res;
    } catch (IOException e) {
      throw new RuntimeException(e);
    }
  }
}

MailServlet.java

public class MailServlet extends HttpServlet {

  protected void doGet(HttpServletRequest request, HttpServletResponse response)
      throws ServletException, IOException {
    Session session = lookupMailSession();
    MailSender sender = new MailSenderImpl(session);

    sender.connect();
    try {
      sender.send("[email protected]", "件名test1", "本文test1");
      sender.send("[email protected]", "件名test2", "本文test2");
    } finally {
      sender.close();
    }
  }

  private Session lookupMailSession() throws ServletException {
    try {
      Context initCtx = new InitialContext();
      Context envCtx = (Context) initCtx.lookup("java:comp/env");
      return (Session) envCtx.lookup("mail/Session");
    } catch (NamingException e) {
      throw new ServletException(e);
    }
  }
}

MailSmtp.properties

mail.smtp.host=localhost
[email protected]
mail.debug=true

#mail.smtp.host=smtp.gmail.com
#mail.smtp.port=587
#mail.smtp.auth=true
#mail.smtp.starttls.enable=true
#[email protected]
#mail.debug=true

MailTestHelper.java

public class MailTestHelper {
  // POP3 polling (Millisec)
  private static final int TIMEOUT = 1000 * 10;
  private final static int WAIT = 500;

  private final Session session;
  private final String address;
  private final String subject;

  public MailTestHelper(Session session, String address, String subject) {
    this.session = session;
    this.address = address;
    this.subject = subject;
  }

  public void delete() {
    handleMessages(Folder.READ_WRITE, true, new MessageHandler() {
      public void handle(Message message) throws Exception {
        message.setFlag(Flags.Flag.DELETED, true);
      }
    });
  }

  public String getContent() {
    List<String> contents = pollingMessages(TIMEOUT, WAIT);
    assertEquals(1, contents.size());
    return contents.get(0);
  }

  private List<String> pollingMessages(int timeoutMillisec, int waitMillisec) {
    MessageGetHandler handler = new MessageGetHandler();
    final int countMax = timeoutMillisec / waitMillisec;
    for (int i = 0; i < countMax; i++) {
      try {
        Thread.sleep(waitMillisec);
        handleMessages(Folder.READ_ONLY, false, handler);
      } catch (InterruptedException e) {
        break;
      }
      if (handler.getSize() > 0) {
        break;
      }
    }
    return handler.getContents();
  }

  private class MessageGetHandler implements MessageHandler {
    private final List<String> contents = new ArrayList<String>();

    public void handle(Message message) throws Exception {
      String res = message.getContent().toString();
      contents.add(res.replaceAll("(\\r\\n){3}$", ""));
    }

    public List<String> getContents() {
      return new ArrayList<String>(contents);
    }

    public int getSize() {
      return contents.size();
    }
  }

  private interface MessageHandler {
    void handle(Message message) throws Exception;
  }

  private void handleMessages(int openMode, boolean expunge,
      MessageHandler handler) {
    Store store = null;
    Folder folder = null;
    try {
      store = session.getStore("pop3");
      store.connect();
      folder = store.getFolder("INBOX");
      folder.open(openMode);
      handleMessages(folder, handler);
    } catch (Exception e) {
      throw new RuntimeException(e);
    } finally {
      try {
        if (folder != null) {
          folder.close(expunge);
        }
        if (store != null) {
          store.close();
        }
      } catch (MessagingException e) {
        e.printStackTrace();
      }
    }
  }

  private void handleMessages(Folder folder, MessageHandler handler)
      throws Exception {
    for (Message message : folder.getMessages()) {
      if (!subject.equals(message.getSubject())) {
        continue;
      }
      if (!address.equals(getAddressTo(message))) {
        continue;
      }
      handler.handle(message);
    }
  }

  private String getAddressTo(Message message) throws MessagingException {
    final Address[] addresses = message.getRecipients(RecipientType.TO);
    assertEquals(1, addresses.length);
    return ((InternetAddress) addresses[0]).getAddress();
  }

  public String getAddress() {
    return address;
  }

  public String getSubject() {
    return subject;
  }
}

Apache James君の設定
http://www.nurs.or.jp/~sug/soft/james/
http://d.hatena.ne.jp/koseki/20060729/standalonesmtp